Field of the Invention
Embodiments of the present invention provide a gas distribution blocker apparatus for improving deposition uniformity on large area substrates.
Description of the Related Art
As demand for larger solar panels and flat panel displays continues to increase, so must the size of substrates and chambers for processing the substrates. One method for depositing material onto a substrate for solar panels or flat panel displays is plasma enhanced chemical vapor deposition (PECVD). In PECVD, process gases are typically introduced across a showerhead in a process chamber through a central gas feed orifice. The process gases diffuse through the showerhead and are ignited into plasma by an RF current applied to the showerhead. The plasma envelops a substrate disposed in a process region of the chamber and deposits thin films on the surface of a substrate.
As substrate sizes increase, the uniformity of the films deposited on the substrate becomes increasingly difficult. Therefore, there is a need for a gas distribution blocker apparatus for altering the flow and pressure differential of process gasses across the surface of a showerhead and improving deposition uniformity on large area substrates.